Four Arab nations cut diplomatic ties with Qatar early Monday morning, further deepening a rift between Gulf Arab nations+ over that country’s support for Islamist groups.

Bahrain, Egypt, Saudi Arabia and the United Arab Emirates all announced they would withdraw their diplomatic staff from Qatar, a gas-rich nation that will host the 2022 FIFA World Cup. Saudi Arabia said Qatari troops would be pulled from its ongoing war in Yemen.

All the nations also said they planned to cut air and sea traffic to the peninsular country. It wasn’t immediately clear how that would affect Qatar Airways, one of the region’s major long-haul carriers.

Qatari officials did not immediately respond to a request for comment.

The decision comes after Qatar alleged in late May that hackers took over the site of its state-run news agency and published what it called fake comments from its ruling emir about Iran and Israel. Its Gulf Arab neighbors responded with anger, blocking Qatari-based media, including the Doha-based satellite news network Al-Jazeera.

The official Saudi state news agency said Saudi Arabia had decided to sever diplomatic and consular relations with Qatar “proceeding from the exercise of its sovereign right guaranteed by international law and the protection of national security from the dangers of terrorism and extremism”.

Saudi Arabia cut all land air and sea contacts with Qatar “and urges all brotherly countries and companies to do the same.”

Bahrain’s foreign affairs ministry issued a statement early Monday saying it would withdraw its diplomatic mission from the Qatari capital of Doha within 48 hours and that all Qatari diplomats should leave Bahrain within the same period.

The ministry’s statement said Qatari citizens needed to leave Bahrain within two weeks and that air and sea traffic between the two countries would be halted. It wasn’t immediately clear how that would affect Qatar Airways, one of the region’s major long-haul carriers.

Bahrain blamed Qatar’s “media incitement, support for armed terrorist activities and funding linked to Iranian groups to carry out sabotage and spreading chaos in Bahrain” for its decision.